The invention relates to a print head for an ink jet printer, comprising a number of ink nozzles for producing ink jets, charging means for charging the ink jets, and also further components assembling the print head. Such a print head is known in practice.
In order to produce quality printing with an ink jet printer, it is necessary for the print head to function properly. Even a minor fault in proper functioning, such as one of the ink spray nozzles becoming fully or partially blocked, can lead to an unacceptable printing result. For that reason, ink jet printers are generally designed in such a way that the print head can be replaced relatively easily. However, a print head is a relatively expensive component and, apart from ink nozzles and charging means (charging electrodes), can comprise further components assembling the print head such as deflecting electrodes, intercepting element and the like, which can be fixed in or on the housing. This leads to wastage and an unnecessarily large stream of waste material. Even if replaced print heads are returned to the manufacturer for recycling of the components which are still usable, this requires additional effort, which increases costs.
The object of the invention is to eliminate the disadvantages of the prior art and to provide a print head for an ink jet printer which does not have to be replaced in full if one of the components is functioning poorly.
To this end, a print head of the type mentioned in the preamble according to the invention is characterized in that the ink nozzles and the charging means are accommodated in an ink jet module which can be detached from the further components assembling the print head.
The invention is based on the insight that a print head composed of easily detachable modules can also be easily disassembled by the end user, so that poorly functioning parts (modules) of the print head can be replaced on the spot. As assembling of the charging means onto the nozzles is relatively difficult, combining of these two parts into one ink jet module, which is easy to exchange, results in a reduced risk of errors, if this exchange is carried out by an unexperienced and/or incompetent person. Furthermore the invention is based on the insight that the ink nozzles and charging means are more sensitive to faults than the other components of the print head, such as deflecting electrodes and intercepting element, and accordingly have to be replaced more frequently. Thereby a considerable cost saving is achieved.
The invention further provides an ink jet unit for use in an ink jet printer provided with a print head according to the invention.